What It Means
External auxiliary outdoor temperature sensor open or shorted.
Trane AC & Heat Pump
Trane AC & Heat Pump Error Code Red 13 Flashes
Troubleshooting guide for the Trane AC & Heat Pump system fault Red 13 Flashes.
ACLogics Fix Trane code Red 13 Flashes See how ACLogics handles it → Fix Red 13 Flashes step-by-step
Possible Causes
- Damaged wiring to auxiliary outdoor sensor.
- Defective external outdoor temperature sensor.
- Control board circuit failure.
Not sure which one it is — or if it's none of these? Try ACLogics today.
Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.
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Full Diagnosis
External outdoor temperature sensor fault (open/shorted).
All Recorded Causes
If an auxiliary outdoor sensor is installed, check its wiring. Replace the sensor if needed. If no separate sensor exists, a technician should examine the control board.
Verify Before Replacing Parts
- Confirm the exact Trane model family and ac and heat pump context before acting on a generic code description.
- Verify the sensor or thermistor reading against the expected range for the current operating condition, keeping in mind that if an auxiliary outdoor sensor is installed, check its wiring.
- Check the sensor harness and board connection before condemning the sensor itself; on Trane units this is also where you'd confirm replace the sensor if needed.
- After the correction, run the system long enough to confirm the ac and heat pump fault does not return under normal load.
Not sure which system this Trane code is on?
ACLogics has guided diagnostics for 36 Trane fault codes and asks the right questions to narrow it down.
